Manufacture of copper sulphate



Patented Mar. 16, 1937 No Drawing. Application April 4, 1935, Serial No. 14,707. In Belgium April 7, 1934 13 Claims. (01. 23-425) 'The'invention relatesto the manufacture of rcopper sulphate.

In prior patent application No. 687,709 dated .August- 31, v1933 for improvements in the Manuiacture of copper sulphate of the same applircant a vprocess hasbeen proposed for manu- :facturing' copper sulphate according to which ithe attack, of the copper is obtained, in the ;presence of air or oxygen, by means of a compound of .chlorine capable of' forming chlorine of .an oxidizing character, and particularly by means of solutions of hydrochloric acid or of :suitable chlorides to which are, added substances I or compounds adapted to promote the formation of the chlorine of oxidizing character.

. its :an addition reagent nitric acid was recomat attackingthelcopper a. mixture of hydro- Jchloricand nitric acids was recommended containing about 15.0 to 80 grams of hydrochloric acid and .5 to 1.0 grams of nitric acid per litre of the liquor respectively. ,Itghasbeen Iound thatj itcopper or a ma- .terial containing, copper is exposed, in the presenceof air oroxygen, to the action of a liquor formed with a solution of hydrochloric acid or .1 a;-.suitable,,,chloridfi..in the presencewof the ion YNI-Ir, itis.possible to attackiand dissolve the copper.

The invention therefore consists in causing to act on copper or on a material containing copper, in the presence of ,air or oxygen, a liquor v containing in solution hydrochloric acid or a suitable chloride in the presence of the ion NH; for the -purposeofwattacking and dissolving the copper subsequently to; be converted into sulphate.

It has further been found that. the attack and the. dissolution of the copper may be conveniently obtained if to the liquor containing hydro- Qchloricacid or a suitable chloride, there is added (either ammonia or an ammonium salt.

Accordingly the invention also. consists in causing to act oncopper, or a material containing copper, and in the presence of air oroxygen, aliquor containing in'solution hydrochloric acid or a suitable chloride in the presence of the ion NI-I4 introduced in the form of ammonia or of an. ammonium saltl V it"whenqthe liquor to beused for the attack c m rises aso qtiim ydr h q acid, good results have been secured when the acid concentration of the liquor is of the order of 70 1. to 39 grams of chlorine per litre and when the liquor comprises a dissolved chloride, gooareing, the copper or a copper bearing material H under the conditions aforesaid, by means of a liquor containing hydrochloric acid with a concentration from 70 to 80 grams of chlorine per litre. of the liquor or a suitable chloride with "an equivalent concentration.

On the other hand it, has been found that if the liquor presents a comparatively high concentration in NH; ions, instead of copper sulphate an ammonium-copper sulphate maybe 1 obtained in the crystallizing tanks. I-Iowever intended.randlamongstgthe solutions to be used such adrawback maybe avoided if the concentration of the liquor in NH4 ions is not over under the conditions stated in the preceding paragraphs, by means of a liquor containing ainmonia or an ammonium salt'in such a quantity that the concentration in NI-L; ions of the liquor does not exceed 20 grams per litre.

As already stated the NH4 ions may be introducedinto the liquor by adding ammonia or an ammonium salt therein, and in this latter case the body associated to the ammonia may be chlorine or a chlorine compound, the chlorine so introduced replacing a part of the chlorine content of the liquor due to the presence of the hydrochloric acid or a salt thereof.

Therefore the invention also consists in attacking copper or a copper bearing material, in

thepre'sence of "air or oxygen, by means of a liquor containing hydrochloric acid orasuitable chloride together with a'compound of ammonia with chlorine or a chlorine compound; When the NH4 ions are introduced in the liquor in the form ofa compound comprising ammonia and chlorine or a chlorine compound, the total concentration of chlorine inthe liquor shall not exceed the chlorine concentration of '70 to 80 grams per litre indicated and preferably the concentration of NH4 ions shall not exceed '20 grams per litre.

Accordingly, the invention further consists in 'causmgeepp'er or a copperb'earing' material to be attacked, in the presence of air or oxygen,

by means of a liquor comprising in solution a compound formed with ammonia and chlorine or a chlorine compound, and in which preferably the concentration in NI-Ir ions does not exceed 20 grams per litre and the chlorine concentration due to the ammonium-chlorine compound or to said compound and an addition of hydrochloric acid or a suitable chloride does not exceed 70 to 80 grams of chlorine per litre.

The copper may be attacked and dissolved in the presence of sulphuric acid, the quantity of which is suitable for the sulphate formation, the liquor loaded with the copper sulphate being carried to the crystallizing tanks in which the copper sulphate is allowed to settle in the usual manner, while the mother liquors, after the concentrations thereof have been restored, are returned to the attack or, alternatively, the copper may be attacked in the absence of sulphuric acid and the copper within the solution converted into sulphate by addition of a suitable quantity of sulphuric acid.

The process may be carried out in any suitable apparatus comprising a tower for the attack including upper and lower chambers separated by a perforated false bottom, pipes issuing into the upper chamber, for introducing the reagents therein, pipes issuing into the lower chamber for supplying air or oxygen to the tower, a pipe leading from the lower part of the tower to the crystallizing tanks and a return pipe for the mother liquors from the crystallizing tanks as well as a pump and fittings to insure the circulation of the liquors between the tower and the crystallizing tanks and eventually the heating of said liquors.

Copper in a divided form such as scraps, hollowshots and the like is introduced within the upper chamber of the tower together with the necessary reagents and air is supplied under pressure to the lower chamber of the tower.

When the attack liquor is suificiently loaded with copper sulphate, the sulphuric acid having been introduced at the same time as the other reagents, it is allowed to flow to the crystallizing tanks in which the sulphate crystals settle, the settling operation being eventually assisted by lowering the temperature; thereafter the mother liquors are restored in their original concentrations and returned to the upper chamber of the tower to execute the same cycle of operations.

If the sulphuric acid is not introduced in the tower, the liquor from the attack having the copper dissolved therein is allowed to flow into a tank located between the tower and the crystallizing tanks, and in which the sulphuric acid is added in the necessary quantity to form the copper sulphate.

The liquor with the sulphate therein is carried to the crystallizing tanks and after settling of the copper sulphate and addition of the reagents to restore the original concentrations the mother liquors are returned to the tower, for a new cycle of operations.

It is to be understood that the details of the process may be modified according to the circumstances and the material acted upon, the process being carried out either in a continuous or intermittent manner.

I claim:

1. A process for manufacturing copper sulphate comprising attacking a copper bearing material, in the presence of an oxygen containing gas by means of a liquor containing in solution chlorine ions and a small quantity of NH4 ions with a concentration not exceeding 20 grams per liter of the liquor thereby causing copper of the copper bearing material to be dissolved, and directly converting the dissolved copper into copper sulphate by means of sulphuric acid.

2. A process for manufacturing copper sulphate comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing in solution chlorine ions and a small quantity of NH4 ions with a concentration not exceeding 20 grams per liter of the liquor, said NH4 ions being introduced into the liquor in the form of ammonia, thereby causing copper of the copper bearing material to be dissolved, and directly converting the dissolved copper into copper sulphate by means of sulphuric acid.

3. A process for manufacturing copper sulphate comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing in solution chlorine ions and a small quantity of NH4 ions with a concentration not exceeding 20 grams per liter of the liquor, said NH4 ions being introduced into the liquor in the form of an ammonium salt, thereby causing copper of the copper bearing material to be dissolved, and directly converting the dissolved copper into copper sulphate by means of sulphuric acid.

4. A process for manufacturing copper sulphate comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing in solution chlorine ions and a small quantity of NH4 ions with a concentration not exceeding 20 grams per liter of the liquor, the concentration of the chlorine into said solution being of the order of '70 to 80 grams per litre, thereby causing copper of the copper bearing material to be dissolved, and directly converting the dissolved copper into copper sulphate by means of sulphuric acid.

5. A process for manufacturing copper sulphate comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing chlorine ions and a small quantity of NI-L ions with a. concentration not exceeding 20 grams per liter of the liquor, said NH4 ions being introduced in the liquor by means of an ammonium chlorine compound, thereby causing copper of the copper bearing material to be dissolved and directly converting the dissolved copper into copper sulphate by means of sulphuric acid.

6. A process in accordance with claim 5, in which the total chlorine concentration does not exceed '70 to 80 grams per litre of the liquor.

7. A process for manufacturing copper sulphate comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing in solution chlorine ions and a quantity of NH. ions not exceeding 20 grams per liter of the liquor and adding sulphuric acid to the reaction, whereby the copper is dissolved and directly converted into copper sulphate, and separating the copper sulphate formed.

8. A process for manufacturing copper sulphate comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing phuric acid thereto and separating therefrom the copper sulphate formed.

9. A process for manufacturing copper sulphate, comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing in solution hydrochloric acid and a small quantity of ammonia the concentration of the NFL ions of the liquor not exceeding 20 grams per liter, thereby causing copper of *the copper bearing material to be dissolved, placing said dissolved copper in the presence of sulphuric acid and thus directly converting it into copper sulphate and separating the copper sulphate formed.

10. A process for manufacturing copper sulphate comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing in solution hydrochloric acid and a small quantity of ammonia in the form of an ammonium salt, the concentration of the NH, ions of the liquor not exceeding 20 grams per liter, thereby causing copper of the copper bearing material to be dissolved, placing said dissolved copper in the presence of sulphuric acid and thus directly converting it into copper sulphate and separating the copper sulphate formed.

11. A process for manufacturing copper sulphate comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing in solution a chloride and a small quantity of ammonia the concentration of the NE ions of the liquor not exceeding 20 grams per liter, thereby causing copper of the copper bearing material to be dissolved, placing said dissolved copper in the presence of sulphuric acid and thus directly converting it into copper sulphate and separating the copper sulphate formed.

12. A process formanufacturing copper sulphate, comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing in solution chlorine ions and a quantity of NH4 ions not exceeding 20 grams per liter of the liquor and adding sulphuric acid to the reaction, whereby the copper is dissolved and converted into copper sulphate while the NHl content of the liquor remains substantially constant, and separating the copper sulphate formed.

13. A continuous process for manufacturing copper sulphate, comprising attacking a copper bearing material, in the presence of an oxygen containing gas, by means of a liquor containing in solution chlorine ions and a quantity of NH4 ions not exceeding 20 grams per liter of the liquor, from time to time adding sulphuric acid to the reaction while the NH content of the liquor remains substantially constant, and separating out the copper sulphate directly formed in the liquor.

MARCEL SERCIRON. 

